Simultaneous voltammetric determination of dopamine and uric acid based on MOF-235 nanocomposite

A highly selective and facile sensing platform based on MOF-235 is fabricated and explored for the synchronous detection of dopamine and uric acid. The MOF-235 material is prepared via a one-step hydrothermal method. The sensing platform is fabricated via drop casting of MOF-235 dispersion on bare glassy carbon electrode (GCE). Then it is sealed using chitosan solution. The as-prepared MOF-235 material has large amount of unsaturated iron metal ions available for electrochemically redox-driven transformation. The aromatic moieties and the uncoordinated carboxylate groups of the MOF-235 are capable of obtain well-separated signals for dopamine (DA) and uric acid (UA), which is attributed to the pi-pi interactions, hydrogen bond and electrostatic action. These characteristics endow the excellent permselectivity and sensitivity for the MOF-235 modified electrode. The designed sensing platform exhibits linear response over concentration range from 10 to 90 mu M for DA, and 10 to 90 mu M for UA with the detect limit of 3.34 mu M for DA and 3.46 mu M for UA separately. To our knowledge, this is the first attempt that MOF-235 is explored the applications in electrochemical determination of medical small molecules. The implementing of MOF-235 in voltammetric detection offers new opportunities for the development of MOF materials based electroanalytical devices.

Automated summary

A highly selective and facile sensing platform based on MOF-235 has been developed for the synchronous detection of dopamine and uric acid. The MOF-235 modified electrode exhibits excellent permselectivity and sensitivity, with linear response over a concentration range and low detection limits for both dopamine and uric acid.